Overall, “real-world practice” studies reflected the use of ibrutinib in younger patients, with more adverse performance status and prognostic factors, as evidenced by a higher proportion of people with relapsed CLL, ECOG ≥ 2, and with 11q and 17p deletions, and included patients on strong as well as moderate or weak CYP3A4 inhibitors and or inducers. Here, CYP3A4 is linked to B-cell chronic lymphocytic leukemia.